Silencer for engines



SPt- 19 1939- H. coANDA 2,173,549

S ILBNCBR FORv ENGINES Filed my 1, 1957 Il I] l 4 INVENTOR= H ENRI COANDA www @L ATTORNEV5 ,im www i 2,173,549l

iuurrsn s'rA'rEsrATt/N'r OFFICE Tcaw einem my 1, m1, ser-uu No. 140.116

, 1n France June 12, i936 1c claim. (ci. 181-60) It is known, inparticular from my prior Patent vention, the silencer is constituted bya series of No. 2,062,869, dated september i. 1936, that a elements. allof the same shape; adapted to be stream of iiuid under pressure escapinginto .the juxtaposed together, and each of these elements atmospherethrough a narrow slot only one lip consists of a main cylindrical part,corresponding g oi' which prolonged in such manner as to deviate to thepartial expansion chamber, carrying two gradually from the axis of saidslot now; along cylindrical extensions, integral therewith, corresaidprolonged lip and eonsequently creates a sponding to the feed conduit,these extensions besuction lin the direction thereof. ing part of acylindrical surface at right angles to -Tne mi; invention relates tomeneer-s or the cylinder forming the expansion chamber and lo muillersbased upon this principle. that is to tangential thereto on the sideopposed to the exm say ofthe type including at least one partial exhaustslot. pension chamber opening into the atmosphere Each of the largediameter cylinders, correthrough atleast one slot made as abovedescribed. sponding to a partial expansion chamber, is Proi The objectof the present invention is to provided with a narrow slot, connectingthe inside to meet the requirements of practice than gunlposed along thegeneratrix of the cylinder, the lar silencers made up to this time, bothfrom the' deilector being located along the inner lip of said point ofview of its operation and from that of slot.- s its construction andassembly. .Ilsl a consequence of the cylindrical shape of According toan/.essential feature of the presthe expansion chambers, there is left,between the ent invention, each partial expansion chamber deiiector ofeach of them and the outer wall of is provided with a defleetor alongthe outlet slot the expansion chamber, an empty space in which thereof,thisI deilector being arranged in such accumulate the exhaust gaseswhich, for some manner that the exhaust gases fed tothe i'lrst reason,after having failed to escape through the g partial expansion chamber,and which have not slot, would tend to ow backward toward said" escapeddirectly through the outlet slot or slotsv slot, so that these gases donot interfere with of said chamber, now 0n to the next partial extheflow of the remainder of the exhaust gases.

pansicn chamber, where they escape at least According to still anotherfeature of the prespartly to the atmosphere through the slot or entinvention, the prolonged lip of the exhaust a slots of said chamber,andsoon, until, practically, slot of each expansion chamber is integralwith in the last chamber, there is no flow of exhaust a curved pieceforming a portion of the cylindrigases, the respective deiiectors ofthevarious cal wall'of the expansion chamber, chambers preventingbackward flow of any por- According to still another feature of theprestion of the gases which would interfere with the ent invention, thedeector provided in each exsmooth running of the gases through thesilencer. pansion chamber consists of a piece, of V-shaped 35 Aparticular object of thezinvention is to longitudinal section, fittinginside the cylindrical provide an arrangement of these deectnrs whichexpansion chamber Vin question, so that, one of does not undfy restrictthe section` of ilow of the branches of the V is the section of aportion themass of gx les through the silencer. o f said piece appliedagainst the inner wall of 7For this purpose, according to-anotherfeature the expansion chamber, whereas the other branch 40 oi' theinvention, whereas the exhaust gases are corresponds to vthe deflectorproper. fed to the partial expansion chambers through According to stillanother feature of the pres conduits extending in the general directionof ent invention, each silencer element is provided flow of said gases,the partial expansion charnwith faces adapted to fit in, or on,correspondbers are in the form oi cylindrical elements exe ing faces ofanother silencer element, whereby all tending at right .angles tothisdirection and of these silencer 'elements can be fitted together acadiameter substantially lgreater than that of curately and withoutspecial diillculty.

said conduits (advantageously twice this diame- Other features of thepresent invention will re;- tcr). Asthe denectors extend from theperiphery suit from the following detailed description of n of saidexpansion chambers toward the 'inside Some Specific embodiments thereof.50

thereof but only to a limited distance, the part of Preferredembodiments of the present inventhe system opposed to the deilect'orsremains untion will be hereinafter described, with reference obstructedand' ail'ords a sumcient passage for to the accompanying drawing, givenmerely by the smooth flowing of the gases. way oi.' example, and inwhich: u g According to another featureof the present inv Fig. 1 is alongitudinal sectionv through one 55 l5 v vide a silencer of this typewhich is better adapted thereof with the atmosphere, advantageously dis-13 element of the silencer, taken on line I I in Fig. 2, and

Fig. 2 la top view of the same element, and' Fig. 3 is a longitudinalsection taken on line III-III in Fig. `4i, through a complete silencercomprising a certain number of elements such as shown in Figs. 1 and 2,while Fig. 4 is a top View of the silencer.

Throughout the views the same references indicate the same orcorresponding parts.

As shown by Figs. 3 and 4, the silencer elements are preferablyassembled between two channel irons U, by `means of which the assembledunit can be mounted upon the body. of a vehicle. A series of cylindersIa, Ib, Ic, Id, Ie, IJ, etc. fitting in each other are assembled betweensaid channel irons in such manner that cylinder Ia ts into vcylinder Ib,cylinder Ic into cylinder Id, and' so forth. Cylinders 261,22), 2c, 2d,2e, 2f, etc. also t in each other so as to form two series extending ina direction parallel to the ilow of the gases. The last cylinder of eachseries same complete 2a, 2c, 2e,etc., and 2b, 2d, 2f, etc. is closed bya plug 3, and each of the lateral openings of cylinders Ia,

Ib, etc. is likewise closed by a washer or plug 4 or 5 respectively sothat the exhaust gases will be caused to flow through narrow slots IIprovided in the walls of the cylinders Ia, Ib, Ic, etc., said slotsbeing preferably arranged along a generatrix either at the top or at thebottom according to the disposition of said'- cylinders with respect tothe silencer unit. Figs. 1 and 2 show the details of an element cast inone pieceincluding one cylinder Ia and one cylinder 2a. Cylinder I lisprovided with a truncated portion .6 adapted to t in a correspondingportion 'l provided in the ad,.- joining cylinder. Cylinder 2a comprisesa recess or female portion 8, into which fits the corresponding maleportion 9 ofthe adjoining cylindrical element. Cylinder la forms apartial expanson chamber into which the gases from cylinder 2apenetrate, ilowing in the direction of arrow F1. The wall of cylinder Iaincludes a part I4 and a delecto'r Il] leaving between these parts avery narrow slot li lip I2 of whichy extends outwardly at I3. Thedeflectorf I0 is preferably of V-shaped longitudinal section having onecircular branch I-Ila extending tangentially to cylinder Ia along onefourth of the circumference thereof, and' one branch penetrating intosaid cylinder and" extending beyond the outer generatrix of cylinder 2a.

The gases arriving in the direction of arrow F1 flow partly along thepath indicated by arrow f and, instead of remaining within the chamberformed by cylinder la, keep flowing toward -chamber Ic formed by thenext cylinder and so forth, thereby expanding more and more. The toplayer of the gases arriving through tube 2a into ,cylinder Ia passesalong part I4 and, iiowing along lip I2 of embossment I3, escapesintothe atmosphere through slot il according to the principle described inPatent No. 2,052,869 of September lst, 1936, for Device for deflecting astream of elastic uid projected into an elastic iluid.

The surrounding air arriving in the direction of arrow qs is thus drawninto the zone along part I3 and increases the suction effect created' bythe expansion of the layer escaping in increased volume through slot II.

rIhe gases which have' own in the-direction indicated by f, i. e. thosewhich have not escaped through slot II and which, due to the resistance'and perpendicularly to each haus't port of the engine, a

offered by the layers of air contained in tube 2, would have a tendencyto ow back rearwardly, will, upon such rearward movement, strike saidreilector so that they are deflected in the directionf'indicated byarrow F2 under the suction effort exerted by the layers of gases ilowingin this direction.

The various tubes formed by the assembly of several cylinders 2.arerigidly secured in place by means of nipples or fingers I 6 carried bywashers 4 and' 5. The exhaust gases arrive into the first small cylinder2 through a suitably shaped socket I1 arranged to t upon the endsthereof; the outer end of socket I'I is provided with a. ilange I8 bymeans of which the silencer unit can be connected to the exhaust of themotor; as already stated slot II preferably extends in a paralleldirection to the generatrix of cylinders I.

It should be understood that the preferred' embodiment of the inventionas shown and described could undergo many modications without departingfrom the spirit or scope of said invention,

this more particularly as regards the means for into the atmosphere, aseries of adjacent elements of identical shape, such element forming twocyl- ,inders of different diameters disposed tangentially andperpendicularly to each other, means feeding the burnt gases to saidelements, and an exhaust opening provided in the wall of one of saidcylinders. i

2. ,-In ay silencer for the exhaustfrom a motor, a series of identicallyshaped adjacent interconnected elements each element forming a wholecomprising two cylinders disposted tangentially other, the diameter ofone of said cylinders being substantially greater than of the othercylinder, a socket connecting the assembled unit of said elements to theexnarrow slot provided in the wall of the larger cylinder and a ilapprotruding outside the cylinder walland extending t rearwardly in regardof the direction otflow in the smaller cylinder. f

, 3. In a silencer for a series ofA identically nected velements eachelement forming `a whole comprising two cylinders disposed tangentiallyand perpendicularly to 'each other, the diameter of one of saidcylinders being substantially greater than of the other cylinder, asocket connecting the assembled unit of said elements to the exhaustport of the engine, an embossment provided upn the inner wall of thelarger cylinder, a narrow slot in the ,wall of the larger cylinderadjoining said embossment, and a flap protruding outside the cylinderwall and extending rearwardly in regard of the direction of flow, in thesmaller cylinder.

4. In a silencer for the vexhaust from a motor, the combination of aseries of identically shaped adjacent lnterconnectedelements eachelement forming a whole comprisingtwo cylinders disposed tangentiallyand perpendicularly to each the exhaust from a motor,

- other, the diameter of one of said cylinders being substantiallygreater than of the othercylinder,

shaped adjacent interconelements, to the exhaust port oi the engine, an

embossment provided'upon the inner wall of the larger cylinder, a narrowslot in the wall of the largercylinder adjoining said embossment, and aap protruding outside the cylinder wall and extending rearwardly invregard of the direction ofy flow, in the-smaller cylinder, wth meansdirecting lthe burnt gases arriving from the smaller cylinder -partlytowards said narrow slots and.'

partly towardsthe other end of the smaller cylinder. ,y 1

5.Ir'1 a silencer for the exhaust from a motor the combination of aseries of identically shaped adjacent interconnected elements eachelement forming awhole comprising two ,cylinders disposed tangentiallyand perpendicularly to each other, the diameter of one of said cylindersbeing substantially greater than of the other,` cylinder, a socketconnecting the assembled unit of -said elements, to the exhaustembossment provided upon the inner wall of the larger cylinder, a narrowslot in the wall of the larger cylinder adjoining said embossment, and aflap protruding outside the cylinder Awall and extending, rearwardly inregard of the direction of flow, in the smaller cylinder, with meansdirecting the -burntgases arriving from the smaller cylinder partlytowards said narrow slots and partly towards the other end oi thesmaller cylinder, and means preventing the return of the burnt gasesfrom one expansion chamber into the preceding one; y

6. In a silencer for the exhaust from a motor, a

series of identically shaped adjacent interconnected elements eachelement forming a whole comprising two cylinders disposed tangentiallyand perpendicularly to each other, the of one of said cylinders beingsubstantially greater than of the other cylinder,Y a socket connectingthe assembled unit of said elements to the exhaust port or the engine,an embossmentA provided upon the inner wall'ot the larger cylinder, anarrow slot` in the wall of the larger cylinder adjoining saidembossment, and a flap protruding outside the cylinder wall andextending rearwardly in regard of the direction 'oi flow, in the smallercylinder, Aand a deilector mounted within the larger cylinder partiallyconfining the aforesaid exhaust slot.

7. A silencer for the exhaust of an engine which comprises,in'combination, a series of partial expansion chambers extending behindone another, a feed conduit for the exhaust gases extending throughoutsaid seriesof chambers, each of said chambers being provided with anexhaust slot opening into the atmosphere, an extension lying in anoutward and. rearward direction with respect to the path oi Athe port ofthe engine, an.

' throughout said series of diameter carriedbythe outer rear lip of saidslot, and a deector carried by the inner front lip of each slotextending inwardly and frontwardly in said chamber.

8. A silencer for the`exhaust of an engine which comprises, incombination, a series of partial expansion chambers extending behind one-another, a feed conduit for the exhaust gases extending throughout saidseries of chambers, each of said chambers being of the shape of acylinder of a diameter substantially greater than that oi said conduithaving its axis at right angles to said conduit, each of said chambersbeing'provided with an exhaust slot opening into the atmosphere, anextension llying in an outward and rearward direction with respect tothe direction of travel o! the gases through said conduit carried by theouter rear lip of said slot, and a deiiector lying in an inward and reardirection in each of said chambers carried by the inner front lip ofeach of s aid chambers.

9. A silencer for the exhaust of an engine which comprises, incombination, a series of partial expansion chambers extending behind oneanother, a feed conduit for the exhaust gases extending chambers, eachof said chambers being of the shape of a cylinder of a diametersubstantially greater than that of said conduit, having its axis atright angles to said conduit, each of said chambersbeing provided withan exhaust slot opening into the atmosphere, and parallel to thegeneratrices ofl said cylinder, an extension l ing in an outward andrearward direction with respect to the direction of travel of the gasesthrough said conduit carried by the rear outer lip of said slot, and adefiector lying 1n the inward and frontward directionin said chamber,carried by the inner iront lip of each of said slots.

10. A silencer for the exhaust of an engine which comprises, incombination, a series of partial explosion chambers extending `behindone another, a cylindrical feed conduit for the exhaust gases extendingthroughout said series of chambers, each of said chambers being ot theshape of a cylinder of a diameter equal to twice that oi' said conduit,having its axis at right angles to said conduit, each of said chambers:being provided with an exhaust slot opening into the atmosphere, andparallel to the generatrices of said chamber, an extension lying in anoutward and rearward direction with respect to the direction of travelof the exhaust gases through said silencer carried by the external rearlip of said slot, and a deiiector lying in the inward andnontwarddirection in said chamber, carried by the inner front lip o!each of said slits.

` HENRI OOANDA.

